Abstract

Because the multiple realization thesis has been offered as an empirical hypothesis, attention must turn to the evidence on its behalf. Some evidence is direct, in the sense that it purports to reveal actual cases of multiple realization. Some is indirect, in the sense that it depends on establishing the truth of hypotheses compatible with multiple realization. This chapter examines direct evidence for multiple realizability, in the form of neural plasticity. The relevant sort of neural plasticity involves cases where damage to the brain results in new brain regions assuming the function of damaged regions, thereby purportedly exhibiting the multiple realization of a psychological state. However, close examination reveals that cases of neural plasticity do not obviously meet the criteria for multiple realization.